Bis-lactam derivatives

ABSTRACT

Gamma-alkyl-gamma-butyrolactones having an alkyl substituent of at least 16 carbon atoms in length, preferably at least 25 carbon atoms, are formed by reacting a monoolefin with a carboxylic acid in the presence of a reducible metal ion of higher-valent form, such as the manganic ion, Mn +3 . The resulting lactones are useful as antiwear agents and for improving the adherence of wax coatings of paper and, upon reaction with amines, polyalkylenepolyamines, for providing novel lactams and bislactams useful as multifunctional agents in lubricants, fuels, coolants and other organic fluids. Thus, the compounds of this invention are of the general structure ##STR1## the alkyl group being as defined above, X being oxygen, imino, alkylimino, polyalkylenepolyamino or lactam(polyalkylenepolyamino) and the dangling valences being hydrogen or lower alkyl (that is, no greater than 6 carbon atoms).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending application Ser. No.336,564 filed Feb. 28, 1973, now abandoned which is acontinuation-in-part of application Ser. No. 799,939, filed on Feb. 17,1969, now abandoned which is a continuation-in-part of application Ser.No. 714,447, filed Mar. 20, 1968, now abandoned. Copending applicationSer. No. 176,267, a continuation-in-part of application Ser. No. 799,939is now U.S. Pat. No. 3,734,865.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to novel gamma-substituted gamma-butyrolactones,and in particular it relates to gamma-alkyl lactams having at least 16carbon atoms in the alkyl substituent and to amine derivatives thereof.

2. Description of the Prior Art

In U.S. Pat. No. 2,296,709 of Fernholz there is disclosedgamma-butyrolactones made by the oxidation of alphatocopherol, not bythe reaction of an olefin with a carboxylic acid. In U.S. Pat. Nos.3,200,075 of Anderson and 3,261,782 of Anderson et al., the lactonesdisclosed contain an amido or a carboxyl substituent on the ringadjacent to the carbonyl carbon atom. The substituent attached to thecarbon atom adjacent to the ring oxygen may contain from 1 to 300 carbonatoms. In U.S. Pat. No. 3,487,452 of Wygant et al, the lactonesdisclosed also contain the alphaamido substituent and an alkylsubstituent of up to 20 carbon atoms. These patents fail to disclosespecific gamma-alkyl-substituted butyrolactones derived from olefinshaving a chain length of at least 16 carbon atoms and carboxylic acids,or their alkylenepolyamine derivatives or the utility of the lactone asa wax coating adherent or the utility of the lactones or the aminederivatives as multifunctional agents in industrial organic fluids.

SUMMARY OF THE INVENTION

In accordance with the present invention, there are provided novelsubstituted gamma-butyrolactones and gamma-butyrolactams having theformula ##STR2## wherein X is oxygen, imino, alkylimino, or an iminolinkage derived from a polyalkylenepolyamine or alactam(polyalkylenepolyamine); wherein R and R' are individuallyhydrogen or alkyl of from 1 to 5 carbon atoms, and each may be the sameor different; R" is hydrogen or alkyl of 1 to 3 carbon atoms; and R'" isan alkyl group containing at least 16 carbon atoms in length, preferablya total of at least 25, and more preferably from 25 to about 100 carbonatoms. When X is an imino, the compound is a lactam or a bis-lactam.Preferably X is derived from a polyalkylenepolyamine:

    >N--(C.sub.n H.sub.2n NH).sub.m --H

or ##STR3## wherein n is an integer of 2 to 4 and m is an integer of 1to 10.

DESCRIPTION OF SPECIFIC EMBODIMENTS

The lactones represented by the general formula shown above can beprepared by the process described in application Ser. No. 714,447 nowabandoned in favor of continuation-in-part application Ser. No. 799,939.The olefinic reactant is a 1- to 4-monoolefin having at least 16 carbonatoms in a straight chain and preferably at a total of 25 to 100 carbonatoms per molecule.

Typical of such olefins are: 1-hexadecene, 1-heptadecene, 1-octadecene,1-eiocosene, 1-pentacosene; 1-hexacosene, 1-heptacosene; 1-octacosene;1-triacontene and polymers of short chain olefins such as ethylene,propylene, butene and isobutene having molecular weights of up to 5000.One such advantageous olefin is a C₃₀ terminal monoolefin having amelting point of 30°-40° C. Internal monoolefins may also be used, butpreferably no higher than 2-olefin and 3-olefin types.

With respect to the carboxylic acid used in preparing the lactams ofthis invention, suitable reactants include acetic, propionic, butyric,pentanoic, hexanoic and heptanoic acids and their isomers. Acetic acidis the preferred reactant.

A preferred method of producing the latter is from a carboxylic acidsolution of the metal ion, e.g. an acetic acid solution of manganicacetate. The solution is heated to temperatures up to the boiling point,or even above the boiling point when pressure is used. It is understoodthat a transient free radical is probably generated via hydrogen lossfrom a molecule of the acid which acts as a ligand to Mn⁺³.

Other useful methods for producing carboxymethyl free radicals aredescribed in application Ser. No. 714,447.

Other free radicals, corresponding to the formula, ##STR4## may begenerated from manganic ions and an acid, e.g. propionic, butanoic,pentanoic and the like. In each case, the acid has at least one alphahydrogen atom. With propionic acid, the free radical ismethylcarboxymethyl, CH₃ CHCOOH; with butanoic acid, it isethylcarboxymethyl, CH₃ CH₂ CHCOOH; and with methylpropionic acid it isdimethylcarboxymethyl, CH₃ (CH₃)CCOOH. In the foregoing free radicalpreparations, the manganic salts could include propionate, butyrate,isobutyrate and hexanoate (caproate).

The preferred metal ion for use in the process for forming the lactonesis trivalent manganese, or manganic ion, Mn⁺³, which is reducible tobivalent manganese, or manganous ion, Mn⁺². Manganic acetate dihydrateis a preferred Mn⁺³ -producing compound. Cerium is also a useful metalin this invention.

The solvent for the reacting monoolefin and the manganese compound, orother metal compound, is preferably an alphahydrogen-containingaliphatic carboxylic acid, in excess quantities of the acid used in thereaction is satisfactory. As stated, acetic acid is the preferredreactant-solvent. Other suitable solvents and details in the process forforming the lactones are made available in said abandoned applicationSer. No. 714,447.

As theorized, the olefin is simply admixed with the metal carboxylate inthe presence of excess carboxylic acid and the temperature is increasedto 150° to 250° C. The following simplified sequence is understood tooccur: ##STR5## If the olefin is a terminal olefin (R"=hydrogen) onlythe gamma carbon is substituted. When acetic acid is used (R andR'=hydrogen) there is no alpha substitution. Straight chain acids of 3or more carbon atoms furnish mono-alpha substitution; 2,2-disubstitutedacids result in di-alpha sustitution. R'" contains at least 16 carbonatoms in length, and preferably has a total carbon atom content of atleast 25. Excess branching is undesirable for reasons of solubility,performance and ease of biodegradability which may be important undercertain uses.

The lactones so produced have utility in increasing the adherentproperties of wax to paper by hot melt technique. Moreover, inhydrocarbon fluid, they provide unexpected antiwear properties.

Upon reaction of the lactones of this invention with tetraethylenepentamine and similar polyalkylene polyamines of the formula H₂N--(C_(n) H_(2n) NH)_(m) --H, wherein n is an integer of 2 to 4 and m isan integer of from 1 to 10, and the removal of water, lactams orbislactams may be produced. Reaction with the amine is believed to openthe lactone ring. However, the removal of water closes the ring againwherein the cyclic oxygen atom has been replaced by the basic nitrogenatom of amine. Accordingly, reactions of 1:1 to 2:1 of lactone to amineprovide useful longchain lactam and bislactam products useful in organicfluids as detergents and antioxidants. Ethylenepolyamines are preferred.

For the purpose of providing such additive properties, it has been foundthat polymeric olefins of propylene and butene and the like are mostsuitable. Polyolefins of molecular weights ranging up to 5000 may beused, and preferably up to about 2000 (about 140 carbon atoms).

The lactones may also be reacted with mono-amines to provide usefulproducts. For example, a butene or isobutene polymer containing about 90carbon atoms and having terminal unsaturation is reacted with manganicacetate to form the lactone, ##STR6## then reacting this with an amine,R_(a) NH₂, to form products like ##STR7## By further treatment of (I)with an amine, R_(a) NH₂, there may be formed ##STR8## Compounds (II)and (III) are also useful as antioxidants. R_(a) is alkyl or aryl offrom 1 to about 20 carbon atoms.

The following examples serve to illustrate and in no sense limit theinvention. All parts are by weight unless otherwise specified.

A. PREPARATION OF LACTONES EXAMPLE 1

A four-neck, five liter flash equipped with a stirrer, thermometer, N₂inlet and a condenser, is charged with 2800 grams of glacial acetic acidand 1200 grams of potassium acetate. The resulting mixture is heated toreflux. A quantity, 210 grams or approximately 0.5 mole, of the C₃₀terminal olefin described above, and 283.5 grams of manganic acetatedihydrate are added to the mixture. After one hour of heating at reflux,a clear solution is obtained. An additional 283.5 grams of the manganicacetate is added, and refluxing is continued for an additional hour,whereupon a clear solution is obtained. The solution is cooled to about20° C. and is diluted with 5 volumes of water. A waxy layer containingthe lactone product forms on top of an aqueous layer and is decanted.

Ethanol (1000 ml) and 50 grams of potassium hydroxide dissolved in 400ml of water are added to the waxy layer, whereupon the potassium salt ofthe lactone is formed. The reaction mixture is refluxed for one hour. Anadditional liter of water is added to the mixture, which is thenextracted with carbon tetrachloride (1000 ml) to remove unreactedolefin. The aqueous layer and CCl₄ layer which are formed are separated.The aqueous layer is acidified with HCl (12N, 100 ml), whereupon thelactone is reformed. The acidified layer is extracted with toluene (500ml). An aqueous layer and a toluene layer which are formed areseparated. The toluene layer is distilled to remove solvents and water,and is concentrated on a rotovac. A light brown product (115.6 grams) isrecovered. Infrared analysis reveals 8 percent of olefin present in theproduct, and vapor phase chromatography indicates a 7% olefin content.The melting point of the product is 35°-50° C.

EXAMPLE 2

Using similar equipment and procedure as that of Example 1, 1-octadeceneis reacted with manganic acetate dihydrate in the presence of excessacetic acid. The resulting reaction mixture is separated as in Example 1in which the organic phase contains gamma-hexadecyl-gamma-butyrolactone.

EXAMPLE 3

Using equipment and reaction conditions similar to that of Example 1, a1-polybutene having a molecular weight of about 830 is reacted withmanganic acetate in the presence of acetic acid. The reaction product isseparated in the same manner as in Example 1 except potassium hydroxideis not used. The organic phase is separated from the aqueous phase byuse of water washes and interfacial separations. The organic phasecontains the corresponding gamma-polybutenyl-gamma-butyrolactone.

EXAMPLE 4

Using conditions similar to that of Example 3, a 1-polybutene ofmolecular weight of about 1380 is reacted with manganic acetate in thepresence of acetic acid. After water washes and separations, the finalorganic phase contains the correspondinggamma-polybutenyl-gamma-butyrolactone.

B. REACTION OF LACTONES WITH AMINES EXAMPLE 5

In a reaction vessel filled with a nitrogen inlet and thermometer, 62.1grams (0.2 mole) of the lactone prepared in accordance with Example 2 ismixed with 18.9 grams (0.1 mole) of tetraethylenepentamine (forbis-lactams: 2:1 of lactone to amine). The reaction mixture is heated at250° F. for 2 days under agitation with periodic nitrogen sweep toremove water vapor. Infrared tracking shows disappearance of the lactoneabsorption at 5.65 microns and appearance of the lactam absorption atabout 6.1 microns. The viscous reaction mixture is mixed with hexane andactivated charcoal; the charcoal is filtered out and the hexane removedby stripping under vacuum. The resulting product contains ##STR9##

EXAMPLE 6

The lactone product of Example 3 and triethylenetetramine are reacted ina manner similar to that of Example 5, using a 2:1 mole ratio, exceptomitting the hexane-charcoal treatment. The reaction product contains##STR10##

EXAMPLE 7

The lactone of Example 4 and triethylenetetramine are reacted in amanner similar to that of Example 6. The reaction product contains##STR11##

EVALUATION OF PRODUCTS

1. antiwear Tests

Three 52-100 steel half-inch diameter balls are held immovable in a ballcup. A fourth ball attached to a rotatable spindle is brought intocontact with the three at a force of 40 kg. and rotated against them ata speed of 600 r.p.m. or 23.3 cm/second, for 30 minutes. The lubricantfor the rotation is cetane containing 0.1% by weight of a lactone. Theball cup and lubricant is held at 200° F. during the test. Thisfour-ball test is a known procedure described in U.S. Pat. No.3,278,432. The lubricant rating is based on the diameter of the weldscar (WSD) on the balls (in mm.) and the wear rate (in cc/cm × 10inches). The lactones of Examples 1 and 2 are evaluated in this testsince they are the only additives in the lubricant fluid. Other lactonesof lower carbon-atom normal olefins are also tested; the heading "R"indicates the number of carbon atoms or, if none, hydrogen, in the gammaposition. The results are:

    ______________________________________                                        R            WSD          Wear Rate                                           ______________________________________                                        No additive  0.775        12.2 and 10.5                                       0            0.815        15.5                                                1            0.838        17.4                                                6            0.766        12.0                                                8            0.735        10.0                                                10           0.756        11.3                                                14           0.804        14.7                                                Example 2    0.718         9.1                                                Example 1    0.674         7.0                                                ______________________________________                                    

The reduced wear of the steel in the last two results indicate theunexpected properties of the long chain gamma-substituted-gamma lactonesof this invention.

The lactone of Example 2 is reacted with triethylenetetramine in thesame manner as in Example 5. The bis-lactam product is added to akerosene jet fuel, JP-7 which meets U.S. Mil. Spec. MIL-T-38219, at aconcentration of 50 ppm. This composition is submitted to thepin-on-disk wear test described in detail in U.S. Pat. No. 3,554,908. Inthis test, the force is 4 kg; the apparatus is run at 46 cm/second at125° F. for 3 hours. The same ratings as in the previous four-ball testare used. The jet fuel is also tested without additive. The results are:

    ______________________________________                                        Additive     WSD          Wear Rate                                           ______________________________________                                        None         2.769        550                                                 Bis-Lactam   1.524        17.1                                                ______________________________________                                    

2. Antioxidant Tests

In this series of tests, a solvent refined mineral oil of 100 SUS at100° F. and 0° F. pour point, containing 1% by weight of the bis-lactamsof this invention, is subjected to oxidation at 175° C. by the followingprocedure: Into a vessel containing 30 grams of the oil compositionoxygen is circulated at 5 liters per hour through a solenoid valve, inwhich the rate of oxygen absorption is measured. The time in hours which1 mole of oxygen per kilogram of oil is absorbed by the oil is obtained;the longer the time the more resistant the oil composition. Alsomeasured is the amount in grams of deposit caused by the oxidationduring the oxidation period; the deposit is washed in hexane beforebeing weighed. A test similar to that used here is described in U.S.Pat. No. 3,554,945. The bis-lactams tested are the products of Examples5, 6 and 7. As a comparison the oil alone and the bis-lactam ofgamma-octyl-gamma-butyrolactone and triethylenetetramine are tested. Theresults are:

    ______________________________________                                                    Absorption                                                        Additive    Time, hrs.   Deposit, grams                                       ______________________________________                                        None        20.0         0.234                                                Octyl-group 28.6         0.4258                                               Example 5   40.1         0.4493                                               Example 6   40.4         0.2755                                               Example 7   35.6         0.3813                                               ______________________________________                                    

The comparison additive in 1% concentration extends the unit oxygenabosrption time only 8 hours, while the products of this inventionextend it 15 to 20 hours. Another comparison additive, abis-polybutenylsuccinimide of tetraethylenepentamine, in which thepolybutene used in preparation has a molecular weight of about 900, alsoin 1% concentration, extends the unit absorption time to only 32.8hours.

A mixture of 0.5% by weight of the product of Example 5 and 0.5% byweight of the said succinimide in the same oil is tested in theoxidation test. The unit absorption time is 42.6 hours.

It will be seen that the lactones and their amine derivatives inaccordance with this invention are useful agents in industrial organicfluids such as lubricants, fuels, greases and the like. They may be usedalone or in conjunction with other additives, such as thepolyalkenylsuccinimides.

Mixed lactones are various alkyl carbon atom lengths may also be used,as shown in Example 8.

EXAMPLE 8

A mixture of C₁₅ to C₂₀ 1-olefins is reacted with manganic acetate inthe presence of acetic acid as described in Example 1, except that themanganic acetate is prepared in situ by adding potassium permanganate insufficient amount to produce conversion to the higher oxidation level.The average chain length of the olefin is about 17. The resultinglactone product is separated and 118.6 grams is mixed with 35.1 grams oftriethylenetetramine in a manner similar to Example 5. Some water isdistilled off to permit the temperature to reach 250° F.

Aspects of this invention have been described in narrow terms, howeverall modifications thereof which would be obvious are considered to bewithin the scope of this invention, as claimed in the following claims:

What is claimed is:
 1. A compound having the structure: ##STR12##wherein the alkyl group has from 16 to 100 carbon atoms; R, R' are R"are individually selected from the group consisting of hydrogen, methyland ethyl; and --N is the amino nitrogen of a lactam polyamine havingthe structure ##STR13## wherein m is an integer of 1 to 10 and R, R' andR" are individually selected as previously defined.
 2. The compound ofclaim 1 wherein both R and R' are hydrogen.
 3. The compound of claim 1wherein said alkyl group is derived from propylene or butene polymer andR" is hydrogen.
 4. The compound of claim 1 wherein said alkyl groupcontains at least 16 carbon atoms in a straight chain.
 5. The compoundof claim 1 wherein m is 3 or
 4. 6. A bis-lactam obtained from agamma-alkyl-gamma-butyrolactone of the formula ##STR14## wherein R, R'and R" are individually selected from the group consisting of hydrogen,methyl and ethyl, and R'" is alkyl having a chain length of 16 to 100carbon atoms, by reacting said butyrolactone with H₂ N(C₂ H₄ NH)_(m) --Hwherein m is an integer of 1 to
 10. 7. The bis-lactam of claim 6 havingthe structure ##STR15## wherein R'" and m are as defined.
 8. Thebis-lactam of claim 6 wherein R'" has a molecular weight of about 800and m is from 3 to
 4. 9. The bis-lactam of claim 6 wherein R'" has amolecular weight of about 1350 and m is from 3 to
 4. 10. The bis-lactamof claim 6 wherein said amine is tetraethylenepentamine and both R andR' are hydrogens.